Modification of the interface and its influence on the performance of W-6 wt% TiC composite

To broaden the application field of tungsten, low-density tungsten-based composites need to be developed. In this study, a W–6 wt% TiC composite with a fine grain size was successfully fabricated by pressureless sintering. Transmission electron microscopy (TEM) analysis shows that the W–TiC interface in the composite is coherent. Furthermore, STEM analysis shows that a Ti-concentration zone (TCZ) with a width of ~30 nm along the W–TiC interface exists in the TiC phase, which is attributed to high defect density in TiC induced by high-energy milling. EBSD analysis shows that the composite has a considerable portion of LAGBs (13.5% in W–W boundaries and 32.5% in TiC–TiC boundaries). The modified interface and fine grain improve the mechanical properties of the composite: the ultimate tensile strength and Vickers hardness reached 630 MPa and 6.72 GPa, respectively. •With pressureless sintering, low-density fine-grained W-TiC composite was successfully fabricated.•13.5% and 32.5% LAGBs in tungsten and TiC phase were achieved without deformation, respectively.•TEM analysis indicates coherent W/TiC interface.•Ti-concentration zone along W/TiC interface was observed and explained.•The ultimate tensile strength and Vickers hardness reached 630 MPa and 6.72 GPa, respectively.